Cell migration assay with 3 cell types - (Nov/09/2009 )

I want to run a cell migration assay in which one cell type (A) has to make a choice to migrate to one of two different other cell types (X and Y). Ideally, this would be carried out in such a way that cells XandY cannot move or migrate in response to each other, and that the cells cannot mingle with each other.

In my dream situation, I would have cell type A in the center of a chamber with X on one side and Y on the other, separated by some time of physical barrier that allows secreted factors to pass through. I know that developmental biologists have utilized similar types of assays to model migration and fate-mapping during development, but I'm not having any luck finding this right now. Does anyone have any suggestions?

thanks!

-skeuos-

You can get transwell inserts for this sort of thing, but I don't know of any system that allows for more than one cell line.